1. Field
The present disclosure relates generally to an improved data processing system and in particular to a method and apparatus for processing data regarding movement of an aircraft. Still more particularly, the present disclosure relates to a computer implemented method, apparatus, and computer usable program product for cross checking required navigation performance procedures.
2. Background
Required navigation performance is a statement about navigation performance necessary for operation within a defined airspace. Required navigation performance provides a process for implementing routes and flight paths that differ from currently used systems in which ground based navigational facilities are employed. Required navigational performance utilizes global positioning satellite data to calculate the position of an aircraft. This position is compared to positional information calculated by other equipment on the aircraft, including inertial navigation systems and distance measuring equipment. The closeness of the calculated positions determines the level of precision for navigational information.
Aircraft using required navigation performance systems may safely operate routes with less separation than is currently required with other navigation systems employing ground-based navigation facilities. This type of system allows for the number of aircraft that can safely use a particular airspace to increase. This type of system may accommodate increasing demand for air traffic capacity.
The level of navigational precision is represented in terms of RNP units. A level of 1.0 RNP is equivalent to an accuracy requiring six thousand feet of separation on either side of an aircraft. A RNP of 0.3 represents increased accuracy and only requires eighteen hundred feet of separation on either side of an aircraft. Currently, when a RNP of 0.3 or less is present, the pilot is no longer flying the aircraft. In this situation, a flight management system executes a required navigation performance procedure to fly the aircraft.
A RNP level of 0.1 requires only six hundred feet of separation on either side of the aircraft. This level is currently the most accurate RNP level used.
An aircraft is guided along a required navigational performance approach procedure path by onboard management systems. These systems are certified navigation computers coupled to the auto pilot system of an aircraft. Flight management systems use their own separate navigational databases and current aircraft position information to guide the aircraft along a predetermined three-dimensional path. The flight management system accomplishes this process by comparing the aircraft's current position in heading to the predetermined approach path. The flight management system may make appropriate adjustments as needed to maintain the path defined by the procedure.